Machine tools

ABSTRACT

Two groups of machines, for broaching or otherwise machining the roots and tips respectively of workpieces such as turbine and compressor blades, are arranged in a single line. Each group is served by a separate free flow conveyor which carries workholders, each containing a workpiece, to each machine in turn and transfer mechanism arranged between the two groups of machines is operable to remove each workpiece from its workholder on one conveyor, rotate it through 180* and return it to a workholder on the other conveyor.

United States Patent [1 1 Archibald [54] MACHINE TOOLS [75] Inventor:Ronald L. Archibald, Bushey, En-

gland [73] Assignee: The Lapointe Machine Tool Company Limited, Watford,England [22] Filed: June 5, 1970 [21] Appl. No.: 43,912

[30] Foreign Application Priority Data 214/1 B, 1 BB, 1 BC; 193/35 A, 35G [451 Apr. 10, 1973 2,176,121 10/1939 Bornett 2,986,261 5/1961Wensu'and 198/25 X 2,792,097 5/1957 Remmen 193/35 A 2,988,237 6/1961Devo] ..2l4/1 BC Primary Examiner-Even C. Blunk AssistantExaminer-Douglas D. Watts Attorney-Roberts, Cushman & Grover 5 7]ABSTRACT Two groups of machines, for broaching or otherwise machiningthe roots and tips respectively of workpieces such as turbine andcompressor blades, are arranged in a single line. Each group is servedby a separate free flow conveyor which carries workholders, eachcontaining a workpiece, to each machine in turn' and transfer mechanismarranged between the two groups of machines is operable to remove eachworkpiece from its workholder on one conveyor,

[56] References cued rotate it through 180 and return it to a workholderon UNITED STATES PATENTS the other on eyor.

2,297,898 10/1942 Kohler .198/25 X 7 Claims, 8 Drawing Figures -r in 1WI J g g g 1 1| 1| u U r L 2 2 l!- 7 -v' s, s

A a T '5 5 a l I l r 5 15 1 e t-5L, 1 3 n [mi 7 7 FIG. 1.

PATENTED m1 0 ms sum 1 OF '3 PATENTED APR 1 01973 SHEET 2 0F 8 PATENTEDAPRI 0 I973 SHEET 3 0F 8 PAIENIEM M 3.726.384

' sum u [If 8 PATENTEDAPR 1 01973 SHEET 7 [IF 8 PMENIEB 3,726,384

SHEET 8 [1F 8 MACHINE TOOLS This invention relates to apparatus of thekind, hereinafter referred to as the kind described, comprising aplurality of work stations at each of which one of a plurality ofmachining operations is performed upon a workpiece which is carried in aworkholder to each station in turn by endless conveying means, and itsobject is to provide apparatus of this kind for operating uponworkpieces such as turbine and compressor blades which require to bemachined at both ends.

To this end, it has already been proposed to divide the work stationsinto two groups, one of which is arranged in a line adjacent one side ofa first endless conveyor and the other of which is arranged in a lineadjacent the opposite side of a second endless conveyor which is offsetparallel to and overlaps the first conveyor between the groups of workstations, and to provide means located adjacent to the overlappingportions of the conveyors for transferring a partly machined workpiecefrom a workholder on the first conveyor to another workholder on thesecond conveyor.

To the same end, according to the present invention, I

it is now proposed to provide two groups of work stations arranged inseries in a single line adjacent one side of said endless conveyingmeans and transfer means located between the last work station in thefirst of said groups and the first work station in the second of saidgroups, for removing a workpiece from a workholder which has beenconveyed past said first group of work stations, rotating it through 180and loading it into another workholder on said conveying means forpassage past said second group of work stations.

A preferred form of the invention will be described, by way of example,with reference to the accompanying drawings in which:

FIG. 1 is a diagrammatic plan view, with parts broken away, of atransfer line for broaching the roots and tips of aircraft engineturbine and compressor blades;

FIG. 2 is an enlarged plan view of a part of FIG. 1 showing thearrangement for transferring workpieces from a conveyor serving onegroup of work stations to a conveyor serving the other group of workstations;

FIG. 3 is an elevation looking in the direction of the arrow III in FIG.2;

FIG. 4 is an enlarged section on the line IV-IV of FIG. 2;

FIG. 5 is an enlarged section on the line V-V of FIG. 2;

FIG. 6 is an enlarged section on the line VI-VI of FIG. 3;

FIG. 7 is an enlarged section on the line VII-VII of FIG. 2; and

FIG. 8 is an enlarged section on the line VIII-VIII of FIG. 2.

Referring to FIG. 1, a line of vertical surface broaching machines 1each having a work fixture 2 is arranged along one side of an endlessfree-flow conveyor 3, along the other side of which are arrangedhydraulic rams 4 each positioned opposite one of the work fixtures. Theupper run of the conveyor 3 moves from left to right as viewed in FIG. 1and transfer means indicated diagrammatically at 5 and 6 serve toconnect opposite ends of the conveyor to the ends of an endlessfree-flow storage conveyor 7 situated below the level of the conveyor 3.In similar fashion, a second line of vertical surface broaching machines8, each having a work fixture 9, is arranged along one side of a secondendless free-flow conveyor 10, along the other side of which arearranged hydraulic rams 11 each positioned opposite one of the workfixtures 9. The upper run of the conveyor 10 also runs from left toright, as viewed in FIG. 1, and transfer means 12 and 13 serve toconnect opposite ends of the conveyor 10 to the ends of an endlessfree-flow storage conveyor 14 situated below the level of the conveyor10. The conveyor 7 which moves from right to left, as viewed in FIG. 1,serves to store a plurality of workholders (not shown) and the transfermeans 5 is operable to transfer a workholder from the discharge end ofthe conveyor 7 to the input end of the conveyor 3 where a blade (notshown), which has previously been encapsulated in a rectangular block ofa stable low-melting-point alloy, is loaded into the workholder with itsroot end pointing towards the work fixtures, 2. One of a plurality ofgates 15 arranged at intervals above the conveyor 3 serves to arrest aworkholder at the input end of the conveyor while an encapsulated bladeis loaded into it and the gate is then raised to permit the workholderto proceed to a point opposite the first work fixture 2 where it isagain arrested by another gate 15. Associated with this gate is a limitswitch which is closed by the workholder to initiate operation of theassociated ram 4 to transfer the blade from the workholder into thefixture 2 with its root end presented to the first broaching machine 1.The latter is then operated to broach the blade, after which the ram 4returns the blade to the workholder, the gate 15 is lifted and theworkholder is carried to the next work station where the aforesaidoperations are repeated. At one or more stations the ram 4 may beoperable to rotate a blade through a predetermined angle before pushingit into the work fixture 2. When the workholder reaches the dischargeend of the conveyor 3 the blade is transferred therefrom by a hydraulicram 16 into an unload fixture l7 and the workholder is returned by thetransfer means 6 to the input end of the storage conveyor 7 and iscarried to the discharge end thereof for use again when required. Fromthe unload fixture the blade is transferred to a load fixture 18 at theinput end of the conveyor 10 by the means to be described hereinafterwith particular reference to FIGS. 2 to 8, which means also serves torotate the blade through At the load fixture 18 the blade is inserted ina further workholder (not shown) which has been transferred by means 12from the conveyor 14 to the input end of the conveyor 10 and carries theblade along the line of work fixtures 9 with its tip presented forbroaching at each of the machines 8 in the manner already described withreference to the first line of machines. At the discharge end of theconveyor 10 the blade is removed from the workholder, inspected andpassed to a sorting mechanism (not shown) which, upon the basis ofinformation received from the inspecting station, either rejects it orpasses it to a decapsulation and cleaning unit. At the same time, thetransfer means 13 returns the empty workholder to the conveyor 14 whereit is stored until it is required again.

On the side of the unload fixture l7 remote from the conveyor 3 is aturntable 19 which extends between the fixture 17 and the input end ofan endless free-flow conveyor 20 extending parallel to and at a levellower than the conveyor 3. The turntable 19 is carried at the upper endof a pillar 21 (FIG. 3) the lower end of which is secured to the rod 22of a hydraulic ram 23 which is operative to raise and lower theturntable between the levels of the conveyors 3 and 20. The pillar 21 isslidably mounted in and keyed at 24 (FIG. 4) for rotation with a sleeve25 which is rotatably mounted in bearings 26 on the machine frame and issecured to a pinion 27 loosely surrounding the pillar 21 and meshingwith a rack 28 slidable horizontally in a fixed guide 29 and secured atone end to the piston rod 30 (FIG. 2) of a hydraulic ram 31. Theturntable 19 comprises a base portion 32 provided with a longitudinallyextending rack 33 and a movable platform 34 carrying a pinion 35 (FIG.5) meshing with the rack 33 and rotatable by a hydraulic motor 36mounted on the platform. A bracket 37 welded to the platform 34 carriesa block 38 formed with ports 39 and 40 for selective connection to anexternal source of hydraulic pressure fluid and opening into a chamber41, formed in the block, on opposite sides of an oscillatory vane 42fixed upon a shaft 43 carrying the upper one of a pair of jaws 44. Theshaft 43 also carries a toothed quadrant which meshes with a toothedquadrant 46 on the shaft 47 of the lower of the jaws 44.

With a blade in position in the unload fixture 17 and the turntable 19in its raised position, pressure fluid is supplied to the motor 36 torotate the pinion 35 which, in co-operation with the rack 33, moves theplatform 34 towards the fixture 17 until the blade is between the jaws44. Pressure fluid is then supplied through the port 39 to theright-hand side of the chamber 41 to move the vane 42 in ananti-clockwise direction as viewed in FIG. 5. Movement of the vane 42 istransmitted through the shaft 43 to the upper jaw 44 and through thequadrants 45 and 46 to the lower jaw to close the jaws on the blade. Themotor 36 is then rotated in the opposite direction to retract theplatform 34 and draw the blade out of the fixture 17, the ram 23 isoperated to lower the turntable 19 and the ram 31 is operated to movethe rack 28 to the right as viewed in FIGS. 2 and 3 to rotate theturntable 19 through 180 through the medium of the pinion 27. The motor36 is once again operated to move the jaws 44 out over the conveyor 20and the jaws are opened to deposit the blade onto the conveyor.

Initial movement of the blade on the conveyor 20 is controlled by a gate48 which is secured to the lower end of the piston rod 49 (FIG. 6) of ahydraulic ram 50 which is carried by a bracket 51 secured to one side ofthe conveyor frame 52 and provided with guides 53 for guide rods 54 onthe gate. The gate 48 is lifted by the ram 50 to permit the blade tomove along the conveyor 20 and is lowered again to await delivery of thenext blade from the turntable 19.

The conveyor 20 passes beneath another gate 55 which is pivotallymounted on a rod 56 (FIG. 7) carried in brackets 57 welded to thecross-member 58 of a gantry carried by opposite sides of the conveyorframe. The cross-member 58 carries brackets 59 which serve to support ahydraulic ram 60 the piston rod 61 of which is secured at its lower endto a beam 62 pivotally mounted on a shaft 63 carried by brackets 64secured to the gate 55. At one side of the conveyor 20, in front of thegate 55 in the direction of movement of the'conveyor, is mounted ahydraulic ram 65 the piston rod 66 of which is secured to a plate 67which carries rods 68 slidable in guides 69. At the side of the conveyor20 opposite the ram 65 is arranged a buffer store (not shown) into whichblades halted by the gate 55 and swept from the conveyor by the plate 67on the ram 65 can be stored until required. Operation of the ram 60 iseffective to swing the gate 55 about its pivot to enable a blade passingdirect from the turntable 19 or returned from the buffer store to movefarther along the conveyor 20.

The conveyor 20 passes beneath two further gates 70 and 71 pivotallysuspended from an arm 72 (FIG. 8)

pivoted at 73 on a bracket 74 secured by bolts 75 to a lic ram 82mounted on the platform 76. The ram 82 is adapted to swing the arm 72about its pivot 73 to alternately raise and lower the gates 70gand 71which are constrained for vertical movement by pairs of guide members83. A blade on the conveyor 20 is halted first by the gate 70 then bythe gate 71 which, upon being raised, permits the blade to proceed to anunloading point where it is finally halted by an abutment 84 associatedwith a limit switch which initiates operation of a hydraulic ram. 85 totransfer the blade from the conveyor 20 onto a platform 86. The latteris movable vertically by a hydraulic ram 87 to transfer the blade fromthe level of the conveyor 20 to the level of the conveyor 10 and afurther hydraulic ram 88 is operable to transfer the blade inib the loadfixture 18 for insertion into a workholder on the conveyor 10 with itstip pointing toward the work fixtures 9.

Operation of the various hydraulic devices is initiated by limitswitches (not shown) located in the path of movement of the workholdersand workpieces along the various conveyors.

I claim:

1. Apparatus for performing a series of machining operations upon oneend of a workpiece followed by a further series of machining operationson the other end of the workpiece, comprising first and second groups ofwork stations arranged in a single line, first and second longitudinallyaligned, continuously driven endless conveyors arranged alongside saidfirst and second groups of work stations, respectively, for moving workholders past the work stations on each group, said first and secondconveyors having input and discharge ends, transfer means situatedbetween the discharge end of the first conveyor and the input end of thesecond conveyor comprising a continuously driven endless transferconveyor arranged parallel to said first and second conveyors betweenthe discharge and input ends thereof, said transfer conveyor havinginput and discharge ends, a turntable rotatable about a vertical axisbetween the discharge end of said first conveyor and the input end ofsaid transfer conveyor for rotating said workpiece through an unloadfixture interposed between the discharge end of said first conveyor andsaid turntable, hydraulically operated means adjacent the discharge endof said first conveyor for transferring a workpiece from its holder onsaid first conveyor into said unload fixture and a pair of hydraulicallyoperated jaws on said turntable for removing a workpiece from saidunload fixture and depositing it upon said transfer conveyor. 7

2. Apparatus for performing a series of machining operations upon oneend of a workpiece followed by a further series of machining operationson the other end of the workpiece, comprising first and second groups ofwork stations arranged in a single line, first and second Ilongitudinally aligned, continuously driven endless conveyors arrangedalongside said first and second groups of work stations, respectively,for moving work holders past the work stations of each group, said firstand second conveyors having input and discharge ends, transfer meanssituated between the discharge ends of the first conveyor and the inputend of the second conveyor comprising a continuously driven endlesstransfer conveyor extending parallel to said first and second conveyorsand located at a level below that of said first and second conveyors, aturntable rotatable about a vertical axis between the discharge end ofthe first conveyor and the input end of said transfer conveyor forrotating said workpiece through 180, an unload fixture interposedbetween the discharge end of said first conveyor and said turntable,hydraulically operated means adjacent the discharge end of said firstconveyor for transferring a workpiece from its holder on said firstconveyor into said unload fixture, a pair of hydraulically operated jawson said turntable for removing a workpiece from said unload fixture anddepositing it upon said transfer conveyor, and a hydraulic ram formoving the turntable vertically between the levels of the first conveyorand the transfer conveyor.

3. Apparatus for performing a series of machining operations upon oneend of a workpiece followed by a further series of machining operationson the other end of the workpiece, comprising first and second groups ofwork stations arranged in a single line, first and second longitudinallyaligned, continuously driven endless conveyors arranged alongside saidfirst and second groups of work stations, respectively, for moving workholders past the work station of each group, said first and secondconveyors having input and discharge ends, transfer means situatedbetween the discharge end of the first conveyor and the input end of thesecond conveyor, comprising a continuously driven endless transferconveyor parallel to said first and second conveyors, a turntablerotatable about a vertical axis between the discharge end of said firstconveyor and the input end of said transfer conveyor, a gate extendingacross said transfer conveyor at a point intermediate its input anddischarge ends pivotally mounted for movement into and out of the pathof workpieces on said transfer conveyor, and hydraulic means mountedalongside of said transfer conveyor operative to remove workpieceshalted by said gate for transfer to of the workpiece, com risingfirstand second roups of work stations arrange in a single line, first ansecond longitudinally aligned endless conveyors arranged alongside saidfirst and second groups of work stations, respectively, for moving workholders past the work stations of each group, said first and secondconveyors having input and discharge ends, transfer means locatedbetween the discharge end of the first conveyor and the input end of thesecond conveyor, said transfer means comprising a continuously drivenendless transfer conveyor extending parallel to said first and secondconveyors, a turntable rotatable about a vertical axis between thedischarge end of said first conveyor and the input end of said transferconveyor, a platform movable vertically between the levels of thetransfer conveyor and said second conveyor between the output end of thetransfer conveyor and a load fixture adjacent the input end of saidsecond conveyor, and hydraulic means for transferring a workpiece fromsaid transfer conveyor to said platform and from said platform throughsaid load fixture into a work holder on said second conveyor.

5. Apparatus according to claim 22, wherein said turntable is rotated bya hydraulic operated rack meshing with a pinion on a rotatable supportfor said tumtable.

6. Apparatus for performing a series of machining operations upon oneend of a workpiece, followed by a further series of machining operationson the other end of the workpiece, comprising first and second groups ofwork stations arranged in a single file, first and second longitudinallyaligned, continuously driven conveyors arranged along side said firstand second groups of work stations respectively, for moving work holderspast the work stations in each group, first and second continuouslydriven storage conveyors, arranged below the level of said firstmentioned conveyors, transfer means located between the last workstation in said first group and the first work station in the secondgroup for removing workpieces from the work holders which have beenmoved past said first group of work stations, rotating said workpiecesthrough and transferring them to the work holders which are to be movedby the second conveyor past said second group of stations and means forfeeding empty work holders from said first and second storage conveyorsto said first and second conveyors respectively and returning emptyworkholders to said storage conveyors after use.

7. Apparatus according to claim 22, wherein said jaws are mounted on aplatform movable horizontally on said turntable by a hydraulicallyoperated pinion on said platform meshing with a longitudinally extendingrack on said turntable.

1. Apparatus for performing a series of machining operations upon oneend of a workpiece followed by a further series of machining operationson the other end of the workpiece, comprising first and second groups ofwork stations arranged in a single line, first and second longitudinallyaligned, continuously driven endless conveyors arranged alongside saidfirst and second groups of work stations, respectively, for moving workholders past the work stations on each group, said first and secondconveyors having input and discharge ends, transfer means situatedbetween the discharge end of the first conveyor and the input end of thesecond conveyor comprising a continuously driven endless transferconveyor arranged parallel to said first and second conveyors betweenthe discharge and input ends thereof, said transfer conveyor havinginput and discharge ends, a turntable rotatable about a vertical axisbetween the discharge end of said first conveyor and the input end ofsaid transfer conveyor for rotating said workpiece through 180*, anunload fixture interposed between the discharge end of said firstconveyor and said turntable, hydraulically operated means adjacent thedischarge end of said first conveyor for transferring a workpiece fromits holder on said first conveyor into said unload fixture and a pair ofhydraulically operated jaws on said turntable for removing a workpiecefrom said unload fixture and depositing it upon said transfer conveyor.2. Apparatus for performing a series of machining operations upon oneend of a workpiece followed by a further series of machining operationson the other end of the workpiece, comprising first and second groups ofwork stations arranged in a single line, first and second longitudinallyaligned, continuously driven endless conveyors arranged alongside saidfirst and second groups of work stations, respectively, for moving workholders past the work stations of each group, said first and secondconveyors having input and discharge ends, transfer means situatedbetween the discharge ends of the first conveyor and the input end ofthe second conveyor comprising a continuously driven endless transferconveyor extending parallel to said first and second conveyors andlocated at a level below that of said first and second conveyors, aturntable rotatable about a vertical axis between the discharge end ofthe first conveyor and the input end of said transfer conveyor forrotating said workpiece through 180*, an unload fixture interposedbetween the discharge end of said first conveyor and said turntable,hydraulically operated means adjacent The discharge end of said firstconveyor for transferring a workpiece from its holder on said firstconveyor into said unload fixture, a pair of hydraulically operated jawson said turntable for removing a workpiece from said unload fixture anddepositing it upon said transfer conveyor, and a hydraulic ram formoving the turntable vertically between the levels of the first conveyorand the transfer conveyor.
 3. Apparatus for performing a series ofmachining operations upon one end of a workpiece followed by a furtherseries of machining operations on the other end of the workpiece,comprising first and second groups of work stations arranged in a singleline, first and second longitudinally aligned, continuously drivenendless conveyors arranged alongside said first and second groups ofwork stations, respectively, for moving work holders past the workstation of each group, said first and second conveyors having input anddischarge ends, transfer means situated between the discharge end of thefirst conveyor and the input end of the second conveyor, comprising acontinuously driven endless transfer conveyor parallel to said first andsecond conveyors, a turntable rotatable about a vertical axis betweenthe discharge end of said first conveyor and the input end of saidtransfer conveyor, a gate extending across said transfer conveyor at apoint intermediate its input and discharge ends pivotally mounted formovement into and out of the path of workpieces on said transferconveyor, and hydraulic means mounted alongside of said transferconveyor operative to remove workpieces halted by said gate for transferto a place of storage and to return workpieces from said place ofstorage to said transfer conveyor.
 4. Apparatus for performing a seriesof machining operations on one end of a workpiece followed by a furtherseries of machining operations on the other end of the workpiece,comprising first and second groups of work stations arranged in a singleline, first and second longitudinally aligned endless conveyors arrangedalongside said first and second groups of work stations, respectively,for moving work holders past the work stations of each group, said firstand second conveyors having input and discharge ends, transfer meanslocated between the discharge end of the first conveyor and the inputend of the second conveyor, said transfer means comprising acontinuously driven endless transfer conveyor extending parallel to saidfirst and second conveyors, a turntable rotatable about a vertical axisbetween the discharge end of said first conveyor and the input end ofsaid transfer conveyor, a platform movable vertically between the levelsof the transfer conveyor and said second conveyor between the output endof the transfer conveyor and a load fixture adjacent the input end ofsaid second conveyor, and hydraulic means for transferring a workpiecefrom said transfer conveyor to said platform and from said platformthrough said load fixture into a work holder on said second conveyor. 5.Apparatus according to claim 22, wherein said turntable is rotated by ahydraulic operated rack meshing with a pinion on a rotatable support forsaid turntable.
 6. Apparatus for performing a series of machiningoperations upon one end of a workpiece, followed by a further series ofmachining operations on the other end of the workpiece, comprising firstand second groups of work stations arranged in a single file, first andsecond longitudinally aligned, continuously driven conveyors arrangedalong side said first and second groups of work stations respectively,for moving work holders past the work stations in each group, first andsecond continuously driven storage conveyors, arranged below the levelof said first mentioned conveyors, transfer means located between thelast work station in said first group and the first work station in thesecond group for removing workpieces from the work holders which havebeen moved past said first group of work stations, rotating saidworkpIeces through 180* and transferring them to the work holders whichare to be moved by the second conveyor past said second group ofstations and means for feeding empty work holders from said first andsecond storage conveyors to said first and second conveyors respectivelyand returning empty workholders to said storage conveyors after use. 7.Apparatus according to claim 22, wherein said jaws are mounted on aplatform movable horizontally on said turntable by a hydraulicallyoperated pinion on said platform meshing with a longitudinally extendingrack on said turntable.